1. Field of the Invention
The present invention relates to a radiographic intensifying screen (hereinafter referred to as "intensifying screen"), and more particularly to an intensifying screen having a fluorescent layer containing a pigment coated phosphor which exhibits excellent radiographic image quality (hereinafter referred to as "image quality").
2. Description of the Prior Art
Radiography is generally classified into two types, viz., medical radiography used for medical diagnosis and industrial radiography used for nondestructive inspection of industrial materials. In both types, the intensifying screen is used in face contact with a radiographic film (hereinafter referred to as "film") to increase the sensitivity of the radiographing system. The intensifying screen is essentially composed of a support such as paper or plastic and a fluorescent layer formed thereon. The fluorescent layer is usually further covered with a transparent protective layer such as polyethylene terephthalate film, acetylcellulose film, polymethacrylate film, nitrocellulose film, etc. The fluorescent layer is composed of a phosphor dispersed in a suitable resinous binder. Some intensifying screens have a reflective layer or an absorptive layer between the support and the fluorescent layer. Further, some intensifying screens used for nondestructive inspection of industrial materials have a metallic foil between the support and the fluorescent layer. In a radiographing system it is important that the intensifying screen should have high image quality and high speed.